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authorAleksey Kladov <[email protected]>2021-06-13 19:44:31 +0100
committerAleksey Kladov <[email protected]>2021-06-13 19:44:31 +0100
commitb292e1b9da39813e2739cb450c263e7502c97c8d (patch)
tree92a09f547c7d7ca41f90ebdc68f0f81ac1805560 /crates/ide/src
parent3478897f86cc1b3e3f83e9d4e7cedff41721fb04 (diff)
internal: refactor missing match arms diagnostics
Diffstat (limited to 'crates/ide/src')
-rw-r--r--crates/ide/src/diagnostics.rs909
-rw-r--r--crates/ide/src/diagnostics/missing_match_arms.rs924
2 files changed, 926 insertions, 907 deletions
diff --git a/crates/ide/src/diagnostics.rs b/crates/ide/src/diagnostics.rs
index 7978c1fc2..01b68232e 100644
--- a/crates/ide/src/diagnostics.rs
+++ b/crates/ide/src/diagnostics.rs
@@ -10,6 +10,7 @@ mod incorrect_case;
10mod macro_error; 10mod macro_error;
11mod mismatched_arg_count; 11mod mismatched_arg_count;
12mod missing_fields; 12mod missing_fields;
13mod missing_match_arms;
13mod missing_ok_or_some_in_tail_expr; 14mod missing_ok_or_some_in_tail_expr;
14mod missing_unsafe; 15mod missing_unsafe;
15mod no_such_field; 16mod no_such_field;
@@ -205,6 +206,7 @@ pub(crate) fn diagnostics(
205 AnyDiagnostic::MacroError(d) => macro_error::macro_error(&ctx, &d), 206 AnyDiagnostic::MacroError(d) => macro_error::macro_error(&ctx, &d),
206 AnyDiagnostic::MismatchedArgCount(d) => mismatched_arg_count::mismatched_arg_count(&ctx, &d), 207 AnyDiagnostic::MismatchedArgCount(d) => mismatched_arg_count::mismatched_arg_count(&ctx, &d),
207 AnyDiagnostic::MissingFields(d) => missing_fields::missing_fields(&ctx, &d), 208 AnyDiagnostic::MissingFields(d) => missing_fields::missing_fields(&ctx, &d),
209 AnyDiagnostic::MissingMatchArms(d) => missing_match_arms::missing_match_arms(&ctx, &d),
208 AnyDiagnostic::MissingOkOrSomeInTailExpr(d) => missing_ok_or_some_in_tail_expr::missing_ok_or_some_in_tail_expr(&ctx, &d), 210 AnyDiagnostic::MissingOkOrSomeInTailExpr(d) => missing_ok_or_some_in_tail_expr::missing_ok_or_some_in_tail_expr(&ctx, &d),
209 AnyDiagnostic::MissingUnsafe(d) => missing_unsafe::missing_unsafe(&ctx, &d), 211 AnyDiagnostic::MissingUnsafe(d) => missing_unsafe::missing_unsafe(&ctx, &d),
210 AnyDiagnostic::NoSuchField(d) => no_such_field::no_such_field(&ctx, &d), 212 AnyDiagnostic::NoSuchField(d) => no_such_field::no_such_field(&ctx, &d),
@@ -545,910 +547,3 @@ pub struct Claims {
545 ); 547 );
546 } 548 }
547} 549}
548
549#[cfg(test)]
550pub(super) mod match_check_tests {
551 use crate::diagnostics::tests::check_diagnostics;
552
553 #[test]
554 fn empty_tuple() {
555 check_diagnostics(
556 r#"
557fn main() {
558 match () { }
559 //^^ Missing match arm
560 match (()) { }
561 //^^^^ Missing match arm
562
563 match () { _ => (), }
564 match () { () => (), }
565 match (()) { (()) => (), }
566}
567"#,
568 );
569 }
570
571 #[test]
572 fn tuple_of_two_empty_tuple() {
573 check_diagnostics(
574 r#"
575fn main() {
576 match ((), ()) { }
577 //^^^^^^^^ Missing match arm
578
579 match ((), ()) { ((), ()) => (), }
580}
581"#,
582 );
583 }
584
585 #[test]
586 fn boolean() {
587 check_diagnostics(
588 r#"
589fn test_main() {
590 match false { }
591 //^^^^^ Missing match arm
592 match false { true => (), }
593 //^^^^^ Missing match arm
594 match (false, true) {}
595 //^^^^^^^^^^^^^ Missing match arm
596 match (false, true) { (true, true) => (), }
597 //^^^^^^^^^^^^^ Missing match arm
598 match (false, true) {
599 //^^^^^^^^^^^^^ Missing match arm
600 (false, true) => (),
601 (false, false) => (),
602 (true, false) => (),
603 }
604 match (false, true) { (true, _x) => (), }
605 //^^^^^^^^^^^^^ Missing match arm
606
607 match false { true => (), false => (), }
608 match (false, true) {
609 (false, _) => (),
610 (true, false) => (),
611 (_, true) => (),
612 }
613 match (false, true) {
614 (true, true) => (),
615 (true, false) => (),
616 (false, true) => (),
617 (false, false) => (),
618 }
619 match (false, true) {
620 (true, _x) => (),
621 (false, true) => (),
622 (false, false) => (),
623 }
624 match (false, true, false) {
625 (false, ..) => (),
626 (true, ..) => (),
627 }
628 match (false, true, false) {
629 (.., false) => (),
630 (.., true) => (),
631 }
632 match (false, true, false) { (..) => (), }
633}
634"#,
635 );
636 }
637
638 #[test]
639 fn tuple_of_tuple_and_bools() {
640 check_diagnostics(
641 r#"
642fn main() {
643 match (false, ((), false)) {}
644 //^^^^^^^^^^^^^^^^^^^^ Missing match arm
645 match (false, ((), false)) { (true, ((), true)) => (), }
646 //^^^^^^^^^^^^^^^^^^^^ Missing match arm
647 match (false, ((), false)) { (true, _) => (), }
648 //^^^^^^^^^^^^^^^^^^^^ Missing match arm
649
650 match (false, ((), false)) {
651 (true, ((), true)) => (),
652 (true, ((), false)) => (),
653 (false, ((), true)) => (),
654 (false, ((), false)) => (),
655 }
656 match (false, ((), false)) {
657 (true, ((), true)) => (),
658 (true, ((), false)) => (),
659 (false, _) => (),
660 }
661}
662"#,
663 );
664 }
665
666 #[test]
667 fn enums() {
668 check_diagnostics(
669 r#"
670enum Either { A, B, }
671
672fn main() {
673 match Either::A { }
674 //^^^^^^^^^ Missing match arm
675 match Either::B { Either::A => (), }
676 //^^^^^^^^^ Missing match arm
677
678 match &Either::B {
679 //^^^^^^^^^^ Missing match arm
680 Either::A => (),
681 }
682
683 match Either::B {
684 Either::A => (), Either::B => (),
685 }
686 match &Either::B {
687 Either::A => (), Either::B => (),
688 }
689}
690"#,
691 );
692 }
693
694 #[test]
695 fn enum_containing_bool() {
696 check_diagnostics(
697 r#"
698enum Either { A(bool), B }
699
700fn main() {
701 match Either::B { }
702 //^^^^^^^^^ Missing match arm
703 match Either::B {
704 //^^^^^^^^^ Missing match arm
705 Either::A(true) => (), Either::B => ()
706 }
707
708 match Either::B {
709 Either::A(true) => (),
710 Either::A(false) => (),
711 Either::B => (),
712 }
713 match Either::B {
714 Either::B => (),
715 _ => (),
716 }
717 match Either::B {
718 Either::A(_) => (),
719 Either::B => (),
720 }
721
722}
723 "#,
724 );
725 }
726
727 #[test]
728 fn enum_different_sizes() {
729 check_diagnostics(
730 r#"
731enum Either { A(bool), B(bool, bool) }
732
733fn main() {
734 match Either::A(false) {
735 //^^^^^^^^^^^^^^^^ Missing match arm
736 Either::A(_) => (),
737 Either::B(false, _) => (),
738 }
739
740 match Either::A(false) {
741 Either::A(_) => (),
742 Either::B(true, _) => (),
743 Either::B(false, _) => (),
744 }
745 match Either::A(false) {
746 Either::A(true) | Either::A(false) => (),
747 Either::B(true, _) => (),
748 Either::B(false, _) => (),
749 }
750}
751"#,
752 );
753 }
754
755 #[test]
756 fn tuple_of_enum_no_diagnostic() {
757 check_diagnostics(
758 r#"
759enum Either { A(bool), B(bool, bool) }
760enum Either2 { C, D }
761
762fn main() {
763 match (Either::A(false), Either2::C) {
764 (Either::A(true), _) | (Either::A(false), _) => (),
765 (Either::B(true, _), Either2::C) => (),
766 (Either::B(false, _), Either2::C) => (),
767 (Either::B(_, _), Either2::D) => (),
768 }
769}
770"#,
771 );
772 }
773
774 #[test]
775 fn or_pattern_no_diagnostic() {
776 check_diagnostics(
777 r#"
778enum Either {A, B}
779
780fn main() {
781 match (Either::A, Either::B) {
782 (Either::A | Either::B, _) => (),
783 }
784}"#,
785 )
786 }
787
788 #[test]
789 fn mismatched_types() {
790 // Match statements with arms that don't match the
791 // expression pattern do not fire this diagnostic.
792 check_diagnostics(
793 r#"
794enum Either { A, B }
795enum Either2 { C, D }
796
797fn main() {
798 match Either::A {
799 Either2::C => (),
800 // ^^^^^^^^^^ Internal: match check bailed out
801 Either2::D => (),
802 }
803 match (true, false) {
804 (true, false, true) => (),
805 // ^^^^^^^^^^^^^^^^^^^ Internal: match check bailed out
806 (true) => (),
807 }
808 match (true, false) { (true,) => {} }
809 // ^^^^^^^ Internal: match check bailed out
810 match (0) { () => () }
811 // ^^ Internal: match check bailed out
812 match Unresolved::Bar { Unresolved::Baz => () }
813}
814 "#,
815 );
816 }
817
818 #[test]
819 fn mismatched_types_in_or_patterns() {
820 check_diagnostics(
821 r#"
822fn main() {
823 match false { true | () => {} }
824 // ^^^^^^^^^ Internal: match check bailed out
825 match (false,) { (true | (),) => {} }
826 // ^^^^^^^^^^^^ Internal: match check bailed out
827}
828"#,
829 );
830 }
831
832 #[test]
833 fn malformed_match_arm_tuple_enum_missing_pattern() {
834 // We are testing to be sure we don't panic here when the match
835 // arm `Either::B` is missing its pattern.
836 check_diagnostics(
837 r#"
838enum Either { A, B(u32) }
839
840fn main() {
841 match Either::A {
842 Either::A => (),
843 Either::B() => (),
844 }
845}
846"#,
847 );
848 }
849
850 #[test]
851 fn malformed_match_arm_extra_fields() {
852 check_diagnostics(
853 r#"
854enum A { B(isize, isize), C }
855fn main() {
856 match A::B(1, 2) {
857 A::B(_, _, _) => (),
858 // ^^^^^^^^^^^^^ Internal: match check bailed out
859 }
860 match A::B(1, 2) {
861 A::C(_) => (),
862 // ^^^^^^^ Internal: match check bailed out
863 }
864}
865"#,
866 );
867 }
868
869 #[test]
870 fn expr_diverges() {
871 check_diagnostics(
872 r#"
873enum Either { A, B }
874
875fn main() {
876 match loop {} {
877 Either::A => (),
878 // ^^^^^^^^^ Internal: match check bailed out
879 Either::B => (),
880 }
881 match loop {} {
882 Either::A => (),
883 // ^^^^^^^^^ Internal: match check bailed out
884 }
885 match loop { break Foo::A } {
886 //^^^^^^^^^^^^^^^^^^^^^ Missing match arm
887 Either::A => (),
888 }
889 match loop { break Foo::A } {
890 Either::A => (),
891 Either::B => (),
892 }
893}
894"#,
895 );
896 }
897
898 #[test]
899 fn expr_partially_diverges() {
900 check_diagnostics(
901 r#"
902enum Either<T> { A(T), B }
903
904fn foo() -> Either<!> { Either::B }
905fn main() -> u32 {
906 match foo() {
907 Either::A(val) => val,
908 Either::B => 0,
909 }
910}
911"#,
912 );
913 }
914
915 #[test]
916 fn enum_record() {
917 check_diagnostics(
918 r#"
919enum Either { A { foo: bool }, B }
920
921fn main() {
922 let a = Either::A { foo: true };
923 match a { }
924 //^ Missing match arm
925 match a { Either::A { foo: true } => () }
926 //^ Missing match arm
927 match a {
928 Either::A { } => (),
929 //^^^^^^^^^ Missing structure fields:
930 // | - foo
931 Either::B => (),
932 }
933 match a {
934 //^ Missing match arm
935 Either::A { } => (),
936 } //^^^^^^^^^ Missing structure fields:
937 // | - foo
938
939 match a {
940 Either::A { foo: true } => (),
941 Either::A { foo: false } => (),
942 Either::B => (),
943 }
944 match a {
945 Either::A { foo: _ } => (),
946 Either::B => (),
947 }
948}
949"#,
950 );
951 }
952
953 #[test]
954 fn enum_record_fields_out_of_order() {
955 check_diagnostics(
956 r#"
957enum Either {
958 A { foo: bool, bar: () },
959 B,
960}
961
962fn main() {
963 let a = Either::A { foo: true, bar: () };
964 match a {
965 //^ Missing match arm
966 Either::A { bar: (), foo: false } => (),
967 Either::A { foo: true, bar: () } => (),
968 }
969
970 match a {
971 Either::A { bar: (), foo: false } => (),
972 Either::A { foo: true, bar: () } => (),
973 Either::B => (),
974 }
975}
976"#,
977 );
978 }
979
980 #[test]
981 fn enum_record_ellipsis() {
982 check_diagnostics(
983 r#"
984enum Either {
985 A { foo: bool, bar: bool },
986 B,
987}
988
989fn main() {
990 let a = Either::B;
991 match a {
992 //^ Missing match arm
993 Either::A { foo: true, .. } => (),
994 Either::B => (),
995 }
996 match a {
997 //^ Missing match arm
998 Either::A { .. } => (),
999 }
1000
1001 match a {
1002 Either::A { foo: true, .. } => (),
1003 Either::A { foo: false, .. } => (),
1004 Either::B => (),
1005 }
1006
1007 match a {
1008 Either::A { .. } => (),
1009 Either::B => (),
1010 }
1011}
1012"#,
1013 );
1014 }
1015
1016 #[test]
1017 fn enum_tuple_partial_ellipsis() {
1018 check_diagnostics(
1019 r#"
1020enum Either {
1021 A(bool, bool, bool, bool),
1022 B,
1023}
1024
1025fn main() {
1026 match Either::B {
1027 //^^^^^^^^^ Missing match arm
1028 Either::A(true, .., true) => (),
1029 Either::A(true, .., false) => (),
1030 Either::A(false, .., false) => (),
1031 Either::B => (),
1032 }
1033 match Either::B {
1034 //^^^^^^^^^ Missing match arm
1035 Either::A(true, .., true) => (),
1036 Either::A(true, .., false) => (),
1037 Either::A(.., true) => (),
1038 Either::B => (),
1039 }
1040
1041 match Either::B {
1042 Either::A(true, .., true) => (),
1043 Either::A(true, .., false) => (),
1044 Either::A(false, .., true) => (),
1045 Either::A(false, .., false) => (),
1046 Either::B => (),
1047 }
1048 match Either::B {
1049 Either::A(true, .., true) => (),
1050 Either::A(true, .., false) => (),
1051 Either::A(.., true) => (),
1052 Either::A(.., false) => (),
1053 Either::B => (),
1054 }
1055}
1056"#,
1057 );
1058 }
1059
1060 #[test]
1061 fn never() {
1062 check_diagnostics(
1063 r#"
1064enum Never {}
1065
1066fn enum_(never: Never) {
1067 match never {}
1068}
1069fn enum_ref(never: &Never) {
1070 match never {}
1071 //^^^^^ Missing match arm
1072}
1073fn bang(never: !) {
1074 match never {}
1075}
1076"#,
1077 );
1078 }
1079
1080 #[test]
1081 fn unknown_type() {
1082 check_diagnostics(
1083 r#"
1084enum Option<T> { Some(T), None }
1085
1086fn main() {
1087 // `Never` is deliberately not defined so that it's an uninferred type.
1088 match Option::<Never>::None {
1089 None => (),
1090 Some(never) => match never {},
1091 // ^^^^^^^^^^^ Internal: match check bailed out
1092 }
1093 match Option::<Never>::None {
1094 //^^^^^^^^^^^^^^^^^^^^^ Missing match arm
1095 Option::Some(_never) => {},
1096 }
1097}
1098"#,
1099 );
1100 }
1101
1102 #[test]
1103 fn tuple_of_bools_with_ellipsis_at_end_missing_arm() {
1104 check_diagnostics(
1105 r#"
1106fn main() {
1107 match (false, true, false) {
1108 //^^^^^^^^^^^^^^^^^^^^ Missing match arm
1109 (false, ..) => (),
1110 }
1111}"#,
1112 );
1113 }
1114
1115 #[test]
1116 fn tuple_of_bools_with_ellipsis_at_beginning_missing_arm() {
1117 check_diagnostics(
1118 r#"
1119fn main() {
1120 match (false, true, false) {
1121 //^^^^^^^^^^^^^^^^^^^^ Missing match arm
1122 (.., false) => (),
1123 }
1124}"#,
1125 );
1126 }
1127
1128 #[test]
1129 fn tuple_of_bools_with_ellipsis_in_middle_missing_arm() {
1130 check_diagnostics(
1131 r#"
1132fn main() {
1133 match (false, true, false) {
1134 //^^^^^^^^^^^^^^^^^^^^ Missing match arm
1135 (true, .., false) => (),
1136 }
1137}"#,
1138 );
1139 }
1140
1141 #[test]
1142 fn record_struct() {
1143 check_diagnostics(
1144 r#"struct Foo { a: bool }
1145fn main(f: Foo) {
1146 match f {}
1147 //^ Missing match arm
1148 match f { Foo { a: true } => () }
1149 //^ Missing match arm
1150 match &f { Foo { a: true } => () }
1151 //^^ Missing match arm
1152 match f { Foo { a: _ } => () }
1153 match f {
1154 Foo { a: true } => (),
1155 Foo { a: false } => (),
1156 }
1157 match &f {
1158 Foo { a: true } => (),
1159 Foo { a: false } => (),
1160 }
1161}
1162"#,
1163 );
1164 }
1165
1166 #[test]
1167 fn tuple_struct() {
1168 check_diagnostics(
1169 r#"struct Foo(bool);
1170fn main(f: Foo) {
1171 match f {}
1172 //^ Missing match arm
1173 match f { Foo(true) => () }
1174 //^ Missing match arm
1175 match f {
1176 Foo(true) => (),
1177 Foo(false) => (),
1178 }
1179}
1180"#,
1181 );
1182 }
1183
1184 #[test]
1185 fn unit_struct() {
1186 check_diagnostics(
1187 r#"struct Foo;
1188fn main(f: Foo) {
1189 match f {}
1190 //^ Missing match arm
1191 match f { Foo => () }
1192}
1193"#,
1194 );
1195 }
1196
1197 #[test]
1198 fn record_struct_ellipsis() {
1199 check_diagnostics(
1200 r#"struct Foo { foo: bool, bar: bool }
1201fn main(f: Foo) {
1202 match f { Foo { foo: true, .. } => () }
1203 //^ Missing match arm
1204 match f {
1205 //^ Missing match arm
1206 Foo { foo: true, .. } => (),
1207 Foo { bar: false, .. } => ()
1208 }
1209 match f { Foo { .. } => () }
1210 match f {
1211 Foo { foo: true, .. } => (),
1212 Foo { foo: false, .. } => ()
1213 }
1214}
1215"#,
1216 );
1217 }
1218
1219 #[test]
1220 fn internal_or() {
1221 check_diagnostics(
1222 r#"
1223fn main() {
1224 enum Either { A(bool), B }
1225 match Either::B {
1226 //^^^^^^^^^ Missing match arm
1227 Either::A(true | false) => (),
1228 }
1229}
1230"#,
1231 );
1232 }
1233
1234 #[test]
1235 fn no_panic_at_unimplemented_subpattern_type() {
1236 check_diagnostics(
1237 r#"
1238struct S { a: char}
1239fn main(v: S) {
1240 match v { S{ a } => {} }
1241 match v { S{ a: _x } => {} }
1242 match v { S{ a: 'a' } => {} }
1243 //^^^^^^^^^^^ Internal: match check bailed out
1244 match v { S{..} => {} }
1245 match v { _ => {} }
1246 match v { }
1247 //^ Missing match arm
1248}
1249"#,
1250 );
1251 }
1252
1253 #[test]
1254 fn binding() {
1255 check_diagnostics(
1256 r#"
1257fn main() {
1258 match true {
1259 _x @ true => {}
1260 false => {}
1261 }
1262 match true { _x @ true => {} }
1263 //^^^^ Missing match arm
1264}
1265"#,
1266 );
1267 }
1268
1269 #[test]
1270 fn binding_ref_has_correct_type() {
1271 // Asserts `PatKind::Binding(ref _x): bool`, not &bool.
1272 // If that's not true match checking will panic with "incompatible constructors"
1273 // FIXME: make facilities to test this directly like `tests::check_infer(..)`
1274 check_diagnostics(
1275 r#"
1276enum Foo { A }
1277fn main() {
1278 // FIXME: this should not bail out but current behavior is such as the old algorithm.
1279 // ExprValidator::validate_match(..) checks types of top level patterns incorrecly.
1280 match Foo::A {
1281 ref _x => {}
1282 // ^^^^^^ Internal: match check bailed out
1283 Foo::A => {}
1284 }
1285 match (true,) {
1286 (ref _x,) => {}
1287 (true,) => {}
1288 }
1289}
1290"#,
1291 );
1292 }
1293
1294 #[test]
1295 fn enum_non_exhaustive() {
1296 check_diagnostics(
1297 r#"
1298//- /lib.rs crate:lib
1299#[non_exhaustive]
1300pub enum E { A, B }
1301fn _local() {
1302 match E::A { _ => {} }
1303 match E::A {
1304 E::A => {}
1305 E::B => {}
1306 }
1307 match E::A {
1308 E::A | E::B => {}
1309 }
1310}
1311
1312//- /main.rs crate:main deps:lib
1313use lib::E;
1314fn main() {
1315 match E::A { _ => {} }
1316 match E::A {
1317 //^^^^ Missing match arm
1318 E::A => {}
1319 E::B => {}
1320 }
1321 match E::A {
1322 //^^^^ Missing match arm
1323 E::A | E::B => {}
1324 }
1325}
1326"#,
1327 );
1328 }
1329
1330 #[test]
1331 fn match_guard() {
1332 check_diagnostics(
1333 r#"
1334fn main() {
1335 match true {
1336 true if false => {}
1337 true => {}
1338 false => {}
1339 }
1340 match true {
1341 //^^^^ Missing match arm
1342 true if false => {}
1343 false => {}
1344 }
1345}
1346"#,
1347 );
1348 }
1349
1350 #[test]
1351 fn pattern_type_is_of_substitution() {
1352 cov_mark::check!(match_check_wildcard_expanded_to_substitutions);
1353 check_diagnostics(
1354 r#"
1355struct Foo<T>(T);
1356struct Bar;
1357fn main() {
1358 match Foo(Bar) {
1359 _ | Foo(Bar) => {}
1360 }
1361}
1362"#,
1363 );
1364 }
1365
1366 #[test]
1367 fn record_struct_no_such_field() {
1368 check_diagnostics(
1369 r#"
1370struct Foo { }
1371fn main(f: Foo) {
1372 match f { Foo { bar } => () }
1373 // ^^^^^^^^^^^ Internal: match check bailed out
1374}
1375"#,
1376 );
1377 }
1378
1379 #[test]
1380 fn match_ergonomics_issue_9095() {
1381 check_diagnostics(
1382 r#"
1383enum Foo<T> { A(T) }
1384fn main() {
1385 match &Foo::A(true) {
1386 _ => {}
1387 Foo::A(_) => {}
1388 }
1389}
1390"#,
1391 );
1392 }
1393
1394 mod false_negatives {
1395 //! The implementation of match checking here is a work in progress. As we roll this out, we
1396 //! prefer false negatives to false positives (ideally there would be no false positives). This
1397 //! test module should document known false negatives. Eventually we will have a complete
1398 //! implementation of match checking and this module will be empty.
1399 //!
1400 //! The reasons for documenting known false negatives:
1401 //!
1402 //! 1. It acts as a backlog of work that can be done to improve the behavior of the system.
1403 //! 2. It ensures the code doesn't panic when handling these cases.
1404 use super::*;
1405
1406 #[test]
1407 fn integers() {
1408 // We don't currently check integer exhaustiveness.
1409 check_diagnostics(
1410 r#"
1411fn main() {
1412 match 5 {
1413 10 => (),
1414 // ^^ Internal: match check bailed out
1415 11..20 => (),
1416 }
1417}
1418"#,
1419 );
1420 }
1421
1422 #[test]
1423 fn reference_patterns_at_top_level() {
1424 check_diagnostics(
1425 r#"
1426fn main() {
1427 match &false {
1428 &true => {}
1429 // ^^^^^ Internal: match check bailed out
1430 }
1431}
1432 "#,
1433 );
1434 }
1435
1436 #[test]
1437 fn reference_patterns_in_fields() {
1438 check_diagnostics(
1439 r#"
1440fn main() {
1441 match (&false,) {
1442 (true,) => {}
1443 // ^^^^^^^ Internal: match check bailed out
1444 }
1445 match (&false,) {
1446 (&true,) => {}
1447 // ^^^^^^^^ Internal: match check bailed out
1448 }
1449}
1450 "#,
1451 );
1452 }
1453 }
1454}
diff --git a/crates/ide/src/diagnostics/missing_match_arms.rs b/crates/ide/src/diagnostics/missing_match_arms.rs
new file mode 100644
index 000000000..6b977fa59
--- /dev/null
+++ b/crates/ide/src/diagnostics/missing_match_arms.rs
@@ -0,0 +1,924 @@
1use hir::InFile;
2
3use crate::diagnostics::{Diagnostic, DiagnosticsContext};
4
5// Diagnostic: missing-match-arm
6//
7// This diagnostic is triggered if `match` block is missing one or more match arms.
8pub(super) fn missing_match_arms(
9 ctx: &DiagnosticsContext<'_>,
10 d: &hir::MissingMatchArms,
11) -> Diagnostic {
12 Diagnostic::new(
13 "missing-match-arm",
14 "missing match arm",
15 ctx.sema.diagnostics_display_range(InFile::new(d.file, d.match_expr.clone().into())).range,
16 )
17}
18
19#[cfg(test)]
20pub(super) mod tests {
21 use crate::diagnostics::tests::check_diagnostics;
22
23 #[test]
24 fn empty_tuple() {
25 check_diagnostics(
26 r#"
27fn main() {
28 match () { }
29 //^^ missing match arm
30 match (()) { }
31 //^^^^ missing match arm
32
33 match () { _ => (), }
34 match () { () => (), }
35 match (()) { (()) => (), }
36}
37"#,
38 );
39 }
40
41 #[test]
42 fn tuple_of_two_empty_tuple() {
43 check_diagnostics(
44 r#"
45fn main() {
46 match ((), ()) { }
47 //^^^^^^^^ missing match arm
48
49 match ((), ()) { ((), ()) => (), }
50}
51"#,
52 );
53 }
54
55 #[test]
56 fn boolean() {
57 check_diagnostics(
58 r#"
59fn test_main() {
60 match false { }
61 //^^^^^ missing match arm
62 match false { true => (), }
63 //^^^^^ missing match arm
64 match (false, true) {}
65 //^^^^^^^^^^^^^ missing match arm
66 match (false, true) { (true, true) => (), }
67 //^^^^^^^^^^^^^ missing match arm
68 match (false, true) {
69 //^^^^^^^^^^^^^ missing match arm
70 (false, true) => (),
71 (false, false) => (),
72 (true, false) => (),
73 }
74 match (false, true) { (true, _x) => (), }
75 //^^^^^^^^^^^^^ missing match arm
76
77 match false { true => (), false => (), }
78 match (false, true) {
79 (false, _) => (),
80 (true, false) => (),
81 (_, true) => (),
82 }
83 match (false, true) {
84 (true, true) => (),
85 (true, false) => (),
86 (false, true) => (),
87 (false, false) => (),
88 }
89 match (false, true) {
90 (true, _x) => (),
91 (false, true) => (),
92 (false, false) => (),
93 }
94 match (false, true, false) {
95 (false, ..) => (),
96 (true, ..) => (),
97 }
98 match (false, true, false) {
99 (.., false) => (),
100 (.., true) => (),
101 }
102 match (false, true, false) { (..) => (), }
103}
104"#,
105 );
106 }
107
108 #[test]
109 fn tuple_of_tuple_and_bools() {
110 check_diagnostics(
111 r#"
112fn main() {
113 match (false, ((), false)) {}
114 //^^^^^^^^^^^^^^^^^^^^ missing match arm
115 match (false, ((), false)) { (true, ((), true)) => (), }
116 //^^^^^^^^^^^^^^^^^^^^ missing match arm
117 match (false, ((), false)) { (true, _) => (), }
118 //^^^^^^^^^^^^^^^^^^^^ missing match arm
119
120 match (false, ((), false)) {
121 (true, ((), true)) => (),
122 (true, ((), false)) => (),
123 (false, ((), true)) => (),
124 (false, ((), false)) => (),
125 }
126 match (false, ((), false)) {
127 (true, ((), true)) => (),
128 (true, ((), false)) => (),
129 (false, _) => (),
130 }
131}
132"#,
133 );
134 }
135
136 #[test]
137 fn enums() {
138 check_diagnostics(
139 r#"
140enum Either { A, B, }
141
142fn main() {
143 match Either::A { }
144 //^^^^^^^^^ missing match arm
145 match Either::B { Either::A => (), }
146 //^^^^^^^^^ missing match arm
147
148 match &Either::B {
149 //^^^^^^^^^^ missing match arm
150 Either::A => (),
151 }
152
153 match Either::B {
154 Either::A => (), Either::B => (),
155 }
156 match &Either::B {
157 Either::A => (), Either::B => (),
158 }
159}
160"#,
161 );
162 }
163
164 #[test]
165 fn enum_containing_bool() {
166 check_diagnostics(
167 r#"
168enum Either { A(bool), B }
169
170fn main() {
171 match Either::B { }
172 //^^^^^^^^^ missing match arm
173 match Either::B {
174 //^^^^^^^^^ missing match arm
175 Either::A(true) => (), Either::B => ()
176 }
177
178 match Either::B {
179 Either::A(true) => (),
180 Either::A(false) => (),
181 Either::B => (),
182 }
183 match Either::B {
184 Either::B => (),
185 _ => (),
186 }
187 match Either::B {
188 Either::A(_) => (),
189 Either::B => (),
190 }
191
192}
193 "#,
194 );
195 }
196
197 #[test]
198 fn enum_different_sizes() {
199 check_diagnostics(
200 r#"
201enum Either { A(bool), B(bool, bool) }
202
203fn main() {
204 match Either::A(false) {
205 //^^^^^^^^^^^^^^^^ missing match arm
206 Either::A(_) => (),
207 Either::B(false, _) => (),
208 }
209
210 match Either::A(false) {
211 Either::A(_) => (),
212 Either::B(true, _) => (),
213 Either::B(false, _) => (),
214 }
215 match Either::A(false) {
216 Either::A(true) | Either::A(false) => (),
217 Either::B(true, _) => (),
218 Either::B(false, _) => (),
219 }
220}
221"#,
222 );
223 }
224
225 #[test]
226 fn tuple_of_enum_no_diagnostic() {
227 check_diagnostics(
228 r#"
229enum Either { A(bool), B(bool, bool) }
230enum Either2 { C, D }
231
232fn main() {
233 match (Either::A(false), Either2::C) {
234 (Either::A(true), _) | (Either::A(false), _) => (),
235 (Either::B(true, _), Either2::C) => (),
236 (Either::B(false, _), Either2::C) => (),
237 (Either::B(_, _), Either2::D) => (),
238 }
239}
240"#,
241 );
242 }
243
244 #[test]
245 fn or_pattern_no_diagnostic() {
246 check_diagnostics(
247 r#"
248enum Either {A, B}
249
250fn main() {
251 match (Either::A, Either::B) {
252 (Either::A | Either::B, _) => (),
253 }
254}"#,
255 )
256 }
257
258 #[test]
259 fn mismatched_types() {
260 // Match statements with arms that don't match the
261 // expression pattern do not fire this diagnostic.
262 check_diagnostics(
263 r#"
264enum Either { A, B }
265enum Either2 { C, D }
266
267fn main() {
268 match Either::A {
269 Either2::C => (),
270 // ^^^^^^^^^^ Internal: match check bailed out
271 Either2::D => (),
272 }
273 match (true, false) {
274 (true, false, true) => (),
275 // ^^^^^^^^^^^^^^^^^^^ Internal: match check bailed out
276 (true) => (),
277 }
278 match (true, false) { (true,) => {} }
279 // ^^^^^^^ Internal: match check bailed out
280 match (0) { () => () }
281 // ^^ Internal: match check bailed out
282 match Unresolved::Bar { Unresolved::Baz => () }
283}
284 "#,
285 );
286 }
287
288 #[test]
289 fn mismatched_types_in_or_patterns() {
290 check_diagnostics(
291 r#"
292fn main() {
293 match false { true | () => {} }
294 // ^^^^^^^^^ Internal: match check bailed out
295 match (false,) { (true | (),) => {} }
296 // ^^^^^^^^^^^^ Internal: match check bailed out
297}
298"#,
299 );
300 }
301
302 #[test]
303 fn malformed_match_arm_tuple_enum_missing_pattern() {
304 // We are testing to be sure we don't panic here when the match
305 // arm `Either::B` is missing its pattern.
306 check_diagnostics(
307 r#"
308enum Either { A, B(u32) }
309
310fn main() {
311 match Either::A {
312 Either::A => (),
313 Either::B() => (),
314 }
315}
316"#,
317 );
318 }
319
320 #[test]
321 fn malformed_match_arm_extra_fields() {
322 check_diagnostics(
323 r#"
324enum A { B(isize, isize), C }
325fn main() {
326 match A::B(1, 2) {
327 A::B(_, _, _) => (),
328 // ^^^^^^^^^^^^^ Internal: match check bailed out
329 }
330 match A::B(1, 2) {
331 A::C(_) => (),
332 // ^^^^^^^ Internal: match check bailed out
333 }
334}
335"#,
336 );
337 }
338
339 #[test]
340 fn expr_diverges() {
341 check_diagnostics(
342 r#"
343enum Either { A, B }
344
345fn main() {
346 match loop {} {
347 Either::A => (),
348 // ^^^^^^^^^ Internal: match check bailed out
349 Either::B => (),
350 }
351 match loop {} {
352 Either::A => (),
353 // ^^^^^^^^^ Internal: match check bailed out
354 }
355 match loop { break Foo::A } {
356 //^^^^^^^^^^^^^^^^^^^^^ missing match arm
357 Either::A => (),
358 }
359 match loop { break Foo::A } {
360 Either::A => (),
361 Either::B => (),
362 }
363}
364"#,
365 );
366 }
367
368 #[test]
369 fn expr_partially_diverges() {
370 check_diagnostics(
371 r#"
372enum Either<T> { A(T), B }
373
374fn foo() -> Either<!> { Either::B }
375fn main() -> u32 {
376 match foo() {
377 Either::A(val) => val,
378 Either::B => 0,
379 }
380}
381"#,
382 );
383 }
384
385 #[test]
386 fn enum_record() {
387 check_diagnostics(
388 r#"
389enum Either { A { foo: bool }, B }
390
391fn main() {
392 let a = Either::A { foo: true };
393 match a { }
394 //^ missing match arm
395 match a { Either::A { foo: true } => () }
396 //^ missing match arm
397 match a {
398 Either::A { } => (),
399 //^^^^^^^^^ Missing structure fields:
400 // | - foo
401 Either::B => (),
402 }
403 match a {
404 //^ missing match arm
405 Either::A { } => (),
406 } //^^^^^^^^^ Missing structure fields:
407 // | - foo
408
409 match a {
410 Either::A { foo: true } => (),
411 Either::A { foo: false } => (),
412 Either::B => (),
413 }
414 match a {
415 Either::A { foo: _ } => (),
416 Either::B => (),
417 }
418}
419"#,
420 );
421 }
422
423 #[test]
424 fn enum_record_fields_out_of_order() {
425 check_diagnostics(
426 r#"
427enum Either {
428 A { foo: bool, bar: () },
429 B,
430}
431
432fn main() {
433 let a = Either::A { foo: true, bar: () };
434 match a {
435 //^ missing match arm
436 Either::A { bar: (), foo: false } => (),
437 Either::A { foo: true, bar: () } => (),
438 }
439
440 match a {
441 Either::A { bar: (), foo: false } => (),
442 Either::A { foo: true, bar: () } => (),
443 Either::B => (),
444 }
445}
446"#,
447 );
448 }
449
450 #[test]
451 fn enum_record_ellipsis() {
452 check_diagnostics(
453 r#"
454enum Either {
455 A { foo: bool, bar: bool },
456 B,
457}
458
459fn main() {
460 let a = Either::B;
461 match a {
462 //^ missing match arm
463 Either::A { foo: true, .. } => (),
464 Either::B => (),
465 }
466 match a {
467 //^ missing match arm
468 Either::A { .. } => (),
469 }
470
471 match a {
472 Either::A { foo: true, .. } => (),
473 Either::A { foo: false, .. } => (),
474 Either::B => (),
475 }
476
477 match a {
478 Either::A { .. } => (),
479 Either::B => (),
480 }
481}
482"#,
483 );
484 }
485
486 #[test]
487 fn enum_tuple_partial_ellipsis() {
488 check_diagnostics(
489 r#"
490enum Either {
491 A(bool, bool, bool, bool),
492 B,
493}
494
495fn main() {
496 match Either::B {
497 //^^^^^^^^^ missing match arm
498 Either::A(true, .., true) => (),
499 Either::A(true, .., false) => (),
500 Either::A(false, .., false) => (),
501 Either::B => (),
502 }
503 match Either::B {
504 //^^^^^^^^^ missing match arm
505 Either::A(true, .., true) => (),
506 Either::A(true, .., false) => (),
507 Either::A(.., true) => (),
508 Either::B => (),
509 }
510
511 match Either::B {
512 Either::A(true, .., true) => (),
513 Either::A(true, .., false) => (),
514 Either::A(false, .., true) => (),
515 Either::A(false, .., false) => (),
516 Either::B => (),
517 }
518 match Either::B {
519 Either::A(true, .., true) => (),
520 Either::A(true, .., false) => (),
521 Either::A(.., true) => (),
522 Either::A(.., false) => (),
523 Either::B => (),
524 }
525}
526"#,
527 );
528 }
529
530 #[test]
531 fn never() {
532 check_diagnostics(
533 r#"
534enum Never {}
535
536fn enum_(never: Never) {
537 match never {}
538}
539fn enum_ref(never: &Never) {
540 match never {}
541 //^^^^^ missing match arm
542}
543fn bang(never: !) {
544 match never {}
545}
546"#,
547 );
548 }
549
550 #[test]
551 fn unknown_type() {
552 check_diagnostics(
553 r#"
554enum Option<T> { Some(T), None }
555
556fn main() {
557 // `Never` is deliberately not defined so that it's an uninferred type.
558 match Option::<Never>::None {
559 None => (),
560 Some(never) => match never {},
561 // ^^^^^^^^^^^ Internal: match check bailed out
562 }
563 match Option::<Never>::None {
564 //^^^^^^^^^^^^^^^^^^^^^ missing match arm
565 Option::Some(_never) => {},
566 }
567}
568"#,
569 );
570 }
571
572 #[test]
573 fn tuple_of_bools_with_ellipsis_at_end_missing_arm() {
574 check_diagnostics(
575 r#"
576fn main() {
577 match (false, true, false) {
578 //^^^^^^^^^^^^^^^^^^^^ missing match arm
579 (false, ..) => (),
580 }
581}"#,
582 );
583 }
584
585 #[test]
586 fn tuple_of_bools_with_ellipsis_at_beginning_missing_arm() {
587 check_diagnostics(
588 r#"
589fn main() {
590 match (false, true, false) {
591 //^^^^^^^^^^^^^^^^^^^^ missing match arm
592 (.., false) => (),
593 }
594}"#,
595 );
596 }
597
598 #[test]
599 fn tuple_of_bools_with_ellipsis_in_middle_missing_arm() {
600 check_diagnostics(
601 r#"
602fn main() {
603 match (false, true, false) {
604 //^^^^^^^^^^^^^^^^^^^^ missing match arm
605 (true, .., false) => (),
606 }
607}"#,
608 );
609 }
610
611 #[test]
612 fn record_struct() {
613 check_diagnostics(
614 r#"struct Foo { a: bool }
615fn main(f: Foo) {
616 match f {}
617 //^ missing match arm
618 match f { Foo { a: true } => () }
619 //^ missing match arm
620 match &f { Foo { a: true } => () }
621 //^^ missing match arm
622 match f { Foo { a: _ } => () }
623 match f {
624 Foo { a: true } => (),
625 Foo { a: false } => (),
626 }
627 match &f {
628 Foo { a: true } => (),
629 Foo { a: false } => (),
630 }
631}
632"#,
633 );
634 }
635
636 #[test]
637 fn tuple_struct() {
638 check_diagnostics(
639 r#"struct Foo(bool);
640fn main(f: Foo) {
641 match f {}
642 //^ missing match arm
643 match f { Foo(true) => () }
644 //^ missing match arm
645 match f {
646 Foo(true) => (),
647 Foo(false) => (),
648 }
649}
650"#,
651 );
652 }
653
654 #[test]
655 fn unit_struct() {
656 check_diagnostics(
657 r#"struct Foo;
658fn main(f: Foo) {
659 match f {}
660 //^ missing match arm
661 match f { Foo => () }
662}
663"#,
664 );
665 }
666
667 #[test]
668 fn record_struct_ellipsis() {
669 check_diagnostics(
670 r#"struct Foo { foo: bool, bar: bool }
671fn main(f: Foo) {
672 match f { Foo { foo: true, .. } => () }
673 //^ missing match arm
674 match f {
675 //^ missing match arm
676 Foo { foo: true, .. } => (),
677 Foo { bar: false, .. } => ()
678 }
679 match f { Foo { .. } => () }
680 match f {
681 Foo { foo: true, .. } => (),
682 Foo { foo: false, .. } => ()
683 }
684}
685"#,
686 );
687 }
688
689 #[test]
690 fn internal_or() {
691 check_diagnostics(
692 r#"
693fn main() {
694 enum Either { A(bool), B }
695 match Either::B {
696 //^^^^^^^^^ missing match arm
697 Either::A(true | false) => (),
698 }
699}
700"#,
701 );
702 }
703
704 #[test]
705 fn no_panic_at_unimplemented_subpattern_type() {
706 check_diagnostics(
707 r#"
708struct S { a: char}
709fn main(v: S) {
710 match v { S{ a } => {} }
711 match v { S{ a: _x } => {} }
712 match v { S{ a: 'a' } => {} }
713 //^^^^^^^^^^^ Internal: match check bailed out
714 match v { S{..} => {} }
715 match v { _ => {} }
716 match v { }
717 //^ missing match arm
718}
719"#,
720 );
721 }
722
723 #[test]
724 fn binding() {
725 check_diagnostics(
726 r#"
727fn main() {
728 match true {
729 _x @ true => {}
730 false => {}
731 }
732 match true { _x @ true => {} }
733 //^^^^ missing match arm
734}
735"#,
736 );
737 }
738
739 #[test]
740 fn binding_ref_has_correct_type() {
741 // Asserts `PatKind::Binding(ref _x): bool`, not &bool.
742 // If that's not true match checking will panic with "incompatible constructors"
743 // FIXME: make facilities to test this directly like `tests::check_infer(..)`
744 check_diagnostics(
745 r#"
746enum Foo { A }
747fn main() {
748 // FIXME: this should not bail out but current behavior is such as the old algorithm.
749 // ExprValidator::validate_match(..) checks types of top level patterns incorrecly.
750 match Foo::A {
751 ref _x => {}
752 // ^^^^^^ Internal: match check bailed out
753 Foo::A => {}
754 }
755 match (true,) {
756 (ref _x,) => {}
757 (true,) => {}
758 }
759}
760"#,
761 );
762 }
763
764 #[test]
765 fn enum_non_exhaustive() {
766 check_diagnostics(
767 r#"
768//- /lib.rs crate:lib
769#[non_exhaustive]
770pub enum E { A, B }
771fn _local() {
772 match E::A { _ => {} }
773 match E::A {
774 E::A => {}
775 E::B => {}
776 }
777 match E::A {
778 E::A | E::B => {}
779 }
780}
781
782//- /main.rs crate:main deps:lib
783use lib::E;
784fn main() {
785 match E::A { _ => {} }
786 match E::A {
787 //^^^^ missing match arm
788 E::A => {}
789 E::B => {}
790 }
791 match E::A {
792 //^^^^ missing match arm
793 E::A | E::B => {}
794 }
795}
796"#,
797 );
798 }
799
800 #[test]
801 fn match_guard() {
802 check_diagnostics(
803 r#"
804fn main() {
805 match true {
806 true if false => {}
807 true => {}
808 false => {}
809 }
810 match true {
811 //^^^^ missing match arm
812 true if false => {}
813 false => {}
814 }
815}
816"#,
817 );
818 }
819
820 #[test]
821 fn pattern_type_is_of_substitution() {
822 cov_mark::check!(match_check_wildcard_expanded_to_substitutions);
823 check_diagnostics(
824 r#"
825struct Foo<T>(T);
826struct Bar;
827fn main() {
828 match Foo(Bar) {
829 _ | Foo(Bar) => {}
830 }
831}
832"#,
833 );
834 }
835
836 #[test]
837 fn record_struct_no_such_field() {
838 check_diagnostics(
839 r#"
840struct Foo { }
841fn main(f: Foo) {
842 match f { Foo { bar } => () }
843 // ^^^^^^^^^^^ Internal: match check bailed out
844}
845"#,
846 );
847 }
848
849 #[test]
850 fn match_ergonomics_issue_9095() {
851 check_diagnostics(
852 r#"
853enum Foo<T> { A(T) }
854fn main() {
855 match &Foo::A(true) {
856 _ => {}
857 Foo::A(_) => {}
858 }
859}
860"#,
861 );
862 }
863
864 mod false_negatives {
865 //! The implementation of match checking here is a work in progress. As we roll this out, we
866 //! prefer false negatives to false positives (ideally there would be no false positives). This
867 //! test module should document known false negatives. Eventually we will have a complete
868 //! implementation of match checking and this module will be empty.
869 //!
870 //! The reasons for documenting known false negatives:
871 //!
872 //! 1. It acts as a backlog of work that can be done to improve the behavior of the system.
873 //! 2. It ensures the code doesn't panic when handling these cases.
874 use super::*;
875
876 #[test]
877 fn integers() {
878 // We don't currently check integer exhaustiveness.
879 check_diagnostics(
880 r#"
881fn main() {
882 match 5 {
883 10 => (),
884 // ^^ Internal: match check bailed out
885 11..20 => (),
886 }
887}
888"#,
889 );
890 }
891
892 #[test]
893 fn reference_patterns_at_top_level() {
894 check_diagnostics(
895 r#"
896fn main() {
897 match &false {
898 &true => {}
899 // ^^^^^ Internal: match check bailed out
900 }
901}
902 "#,
903 );
904 }
905
906 #[test]
907 fn reference_patterns_in_fields() {
908 check_diagnostics(
909 r#"
910fn main() {
911 match (&false,) {
912 (true,) => {}
913 // ^^^^^^^ Internal: match check bailed out
914 }
915 match (&false,) {
916 (&true,) => {}
917 // ^^^^^^^^ Internal: match check bailed out
918 }
919}
920 "#,
921 );
922 }
923 }
924}
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-25 16:59:04 +0000